A009040 Expansion of E.g.f. cos(sin(tanh(x))), even powers only.

1, -1, 13, -373, 18649, -1433129, 156563045, -23043285021, 4392102360241, -1051530622359889, 308633929353801661, -108880766753141666757, 45418989883077539513225, -22097331609699052757909881

Offset

0,3

Links

G. C. Greubel, Table of n, a(n) for n = 0..233

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Cos[Sin[Tanh[x]]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jun 24 2013 *)

Prog

(PARI) x='x+O('x^60); v=Vec(serlaplace(cos(sin(tanh(x))))); vector(#v\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 22 2018

Crossrefs

Sequence in context: A330255 A280796 A183472 * A009085 A012013 A082403

Adjacent sequences: A009037 A009038 A009039 * A009041 A009042 A009043

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Jun 24 2013

Status

approved